They do have subagents, released v2 of that feature with the launch of 5.6 model series in fact. It's just... very poorly executed, is a significant regression from subagents v1 and thousands of miles behind subagents of Claude code.

- Models that can be launched as subagents are hardcoded (can only be another Sol or Terra, but not Luna). Most of the time it'll just launch same model as parent anyway.

- They encrypt initial task delegation from root agent to subagent, for whatever reason

- You can't switch into subagent view at all, despite the fact that apart from initial root>subagent task handoff, all session is visible in transcript.

With Claude you can have "use a lower tier subagent when appropriate" in CLAUDE.md and it'll just work. The "smart" agent goes in a busy loop observing the subagent(s) and will confirm their work afterwards.

(also you need to gate it with "tell the subagent it's a subagent" and "if you are a subagent, don't spawn subagents" or you'll get a matroshka doll of sonnets all the way down =P )

Codex kinda sorta can launch a subagent, but that's about it.